Method for manufacturing erosion control blankets

ABSTRACT

A reinforced or supported core for a roll of erosion control blanket and method of using the same. The core is supported at both lateral ends thereof when the erosion control blanket is attached and during initial stages of winding the erosion control blanket about the core.

During activities such as road construction and landscaping, portions of bare soil are frequently present. These portions of bare soil are subsequently seeded or sodded to reduce or eliminate soil erosion from precipitation and wind. If seeded, the bare soil portions are exposed to erosion until the seeded plants emerge sufficiently to prevent further erosion. If erosion is sufficiently severe, the bare soil portions must be replaned and reseeded, thereby incurring extra time, effort and expense. One solution to protecting otherwise bare portions of soil from erosion is using erosion control blankets. Typically, erosion control blankets have natural fibers such as straw sandwiched between two webs, which are stitched together. After being formed, the erosion control blanked is packaged into rolls for storage and transport. At the site, the erosion control blankets are unrolled over the bare soil either manually or by using implements such as tractors.

When being formed into larger rolls, lengths of erosion control blankets are wrapped around cores, which must withstand the pressures initially exerted when the leading edge of the erosion control blanket is adhered to the core and during initial stages of wrapping. Cores with sufficient strength to withstand these initial forces have been expensive and inconvenient to reuse.

The present invention provides a solution so that lower costing cores having considerably lesser strength can be used, thereby reducing the costs of forming rolls of erosion control blankets.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side view of a device forming an erosion control blanket.

FIG. 2 is a perspective view of the support and core of this invention disposed between a top and bottom roller of the device of FIG. 1.

FIG. 3 is a perspective view of cores suitable for use in forming a roll of erosion control blanket and one embodiment of the support of this invention.

FIG. 4 is a cross sectional view of one embodiment of the instant support disposed in a core.

FIG. 5 is a cross sectional view of a core disposed in another embodiment of the support of this invention.

FIG. 6 is a perspective view of one embodiment of the support of this invention inserted in the present core and of the instant support extending from the core of a bale.

It is understood that the above-described figures are only illustrative of the present invention and are not contemplated to limit the scope thereof.

DESCRIPTION

A typical method for making erosion control blankets is illustrated in FIG. 1 at 100; wherein a fiber is bonded to a substrate, the final product being packaged as a roll for efficient and economical storage, transport, and application. While there are several methods of manufacturing erosion control blankets, the nonlimiting and exemplary method illustrated in FIG. 1 shows a model EMA 2440-04 Production Line Type device made and marketed by mst-MASCHINENBAU GmbH, Twistringen, Germany. However, any of several devices may be used to manufacture erosion control blankets within the scope of this invention. FIG. 1 shows a bale opener 102 opening bales of fiber, in which the fiber is freed from the compacted bales and delivered to a pneumatic conveyor 104, wherein the fiber is conveyed by an air stream generated by blower 106 as indicated by the arrow 108. Fibers such as straw, hay, wood shavings, wool, palm oil fiber, and the like may be suitable for various uses. The air stream distributes the fiber on top of a web 110, which is being dispensed from a roll 112. However, before being delivered atop the web 110, the fiber is compressed between rollers 116 and 118, then between rollers 118 and 120. The rollers 116, 118, and 120 configure the fiber into a mat-like layer having a desired depth and a width matching the width of the web. The matted fiber and underlying web are then further conveyed to where an overlaying web 122 is dispensed from a roll 124. Either or both webs may include materials such as natural or synthetic fibers. Natural fibers include cotton, wool, jute, linen, or the like. Synthetic materials include nylon or other synthetics, optionally readily photodecomposing with exposure to sunlight and weather. At this point, the matted fiber layer is disposed between the underlying web 110 and the overlaying web 122. After the overlaying web 122 has been applied, the underlying web 110 and overlaying lab 122 are stitched together by a stitching machine 126 using thread dispensed from spools 128. The resulting blanket is yet further conveyed and compressed by roller pairs illustrated at 130 and 132 and at 134 and 136. An optional cutting device 138 may be used to sever the blanket if smaller widths are desired. The resulting erosion control blanket 140 is then packaged in a roll 142. Configuring the erosion control blanket 140 into the roll 142 may be accomplished by attaching a leading edge of the erosion control blanket 140 to a core 144 with a fastener such as an adhesive, staple, or the like. While being configured, the roll 142 is rotated and compressed between a pair of lower rollers 146 and 148 and an upper roller 150. When a desired length of erosion control blanket has been configured into the roll 142, the trailing edge of the erosion control blanket is formed by severing the upper and lower webs 122 and 110 and the matted fiber therebetween. After a roll of a desired length has been formed, the roll is removed from between the rollers and palletized for storage and shipping. At the site where the erosion control blanket will be utilized, a length of tubing is inserted inside the core 144, the trailing edge of the erosion control blanket is freed, and the erosion control blanket is unrolled over the soil to be protected from erosion.

Referring to FIG. 2, a core 144 is depicted before the erosion control blanket 140 is wrapped therearound and is positioned between the upper roller 150 and the lower rollers 146 and 148, the roller 148 being shown. The upper roller 150, in the embodiment depicted, has a lateral flange 152 at each end thereof attached to the generally cylindrical roller portion 154. In the embodiment shown, the cylindrical roller portion 154 has an exterior having lands 156 and grooves 158 to better grip the erosion control blanket 140 being wrapped around the core 144. A web 160 may be wrapped around each of the lower soldiers 146 and 148 to better grip the erosion control blanket 140 as the roll 142 is being formed. As the roll 142 is being formed, an end portion 162 of the upper roll 150 exerts a force on an adjoining portion 164 of the core 144 so that the erosion control blanket 140 is pressed against the core 144 and so that the leading edge of the erosion control blanket 140 is adhered to the core 144.

Suitable materials for the core 144 in FIG. 3 include schedule 40 polyvinyl chloride tubing 170 and wrapped paper core tubing 172 having a thickness of at least three-eights inch. Previous experience has shown that tubing having thinner wall thicknesses than provided for by schedule 40 or one half inch paper core is collapsed by the upper roller 150 during the initial phase of attaching the erosion control blanket 140 to the core 144. While cores having the requisite strength can be reused, end-users are often reluctant to extend the time and effort necessary to do so. When not returned, the scores represent an increased expense to manufacturers of erosion control blankets. Referring again to FIG. 3, an alternative core is shown at 174. The core 174 may be made from tubing with a thickness less than that of schedule 40. In the embodiment depicted, the core 174 includes perforated and somewhat flexible drainpipe. However, other materials, such as paper tubing with a considerably reduced wall thickness than depicted at 172 may be used as well.

To prevent the lateral end portions 164 of the core 174 from being crushed during initial stages of forming the roll 142, a support 180 is utilized. In the embodiment depicted, the support 180 is an insert with an outer diameter slightly smaller than the inner diameter of the roll 142. The support 180 may be formed from metals, wood, synthetic resins, or any other material providing the requisite strength to prevent the core 144 from being crushed. Suitable metals include steel, cast-iron, aluminum, and the like. Suitable synthetic resins include schedule 40, or thicker, polyvinyl chloride. However, a person of ordinary skill in the art will readily recognize that other synthetic resins may be suitable for a given embodiment of this invention. Other suitable synthetic resins may be found in the Handbook of Plastics, Elastomers, and Composites, Charles A. Harper, Editor in Chief, Third Edition, McGraw-Hill, New York, 1996, hereby incorporated by reference.

As shown in FIG. 4, the lateral portion 164 of the core 144 is reinforced by the support 180, which may include optional end portions 184 and 186 in some embodiments, the end portion optionally extending beyond the remainder of the support. If a synthetic resin is used, additional weight may be added by inserting soil, scrap metal, or another filler in the cavity 188. If a metal is used, the support 180 may not need additional weight and can be configured as a hollow cylinder, which is easily inserted and removed from within the lateral portion 164. Referring to FIG. 5, another embodiment of the support of this invention is shown as an exsert 190 and includes a generally cylindrical portion 192 and an optional end flange 194. Rather than being inserted inside the core 144, the support 190 is exserted, such that the lateral portion 164 of the core 144 is disposed inside, and supported by, the exsert support 190. FIGS. 4 and 5 show the supports spaced apart from the cores for clarity. However, in practice the supports would contact the cores in some embodiments.

In use, the support of this invention protects the lateral portion 164 of the core 144 by insertion or exsertion and the core 144 is disposed between the upper roller 150 and the lower rollers 146 and 148, for example, as shown in FIG. 2. The leading edge of the erosion control blanket 140 is adhered to the core 144 and the rollers 146, 148, and 150 are rotated, thereby forming the roll 142. When a desired length of erosion control blanket has been wrapped, the rollers are stopped, and the continuous length of the erosion control blanket is severed. The support of this invention is then removed. The erosion control blanket in the roll may be secured by banding, or equivalent means. FIG. 6 depicts the support 180 inserted into the core 174 as well as the support 180 extending from the core 174 of a banded roll 142.

Because numerous modifications of this invention may be made without departing from the spirit thereof, the scope of the invention is not to be limited to the embodiments illustrated and described. Rather, the scope of the invention is to be determined by the appended claims and their equivalents. 

1. A process of manufacturing an erosion control blanket, comprising rolling a fiber attached to a web on a substantially hollow core, the core having a removable support at each end thereof.
 2. The process of claim 1, in which the support is an insert.
 3. The process of claim 1, in which the support is an exsert.
 4. The process of claim 1, further comprising removing each said support.
 5. The process of clam 1, in which each support is generally cylindrical.
 6. The process of claim 1, in which each support comprises steel.
 7. The process of claim 1, in which each support comprises a synthetic resin.
 8. The process of claim 7, in which a filler is disposed inside each support.
 9. The process of claim 7, in which the fiber rolled on the core is stitched to the web.
 10. The process of claim 1, further comprising adhering a leading edge of the erosion control blanket to the core.
 11. The process of claim 10, further comprising severing a desired length of erosion control blanket, thereby forming a roll of an erosion control blanket.
 12. The process of claim 11, further comprising securing the roll of erosion control blanket by banding.
 13. The core of claim 1 in combination with a pair of the supports of claim 1, the inserts supporting each end of the core.
 14. A roll of erosion control blanket, comprising a core, a pair of supports supporting lateral ends of the core, and a length of erosion control blanket wrapped around the core.
 15. The roll of claim 14, in which the supports are inserted into the core lateral ends.
 16. The roll of claim 14, in which the supports are exserted about the core lateral ends.
 17. The roll of claim 14, in which the supports comprise metal, wood, or a synthetic resin.
 18. The roll of claim 14, in which the supports are generally cylindrical.
 19. The roll of claim 18, in which each of the supports comprises an end wall bonded to a generally cylindrical body.
 20. The roll of claim 19, in which the core has a resistance to an external force less that the resistance of schedule 40 polyvinyl chloride tubing. 